Dependence of heterochromatic histone H3 methylation patterns on the Arabidopsis gene DDM1
Dependence of heterochromatic histone H3 methylation patterns on the Arabidopsis gene DDM1
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DOI：
10.1126/science.1074950
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发表时间：
2002-09-13
期刊：
影响因子：
56.9
通讯作者：
Martienssen, RA
中科院分区：
文献类型：
--
作者：
Gendrel, AV;Lippman, Z;Martienssen, RA
拟南芥基因DDM 1需要维持DNA甲基化水平，并负责转座子和转基因沉默。然而，DDM 1不是编码DNA甲基转移酶，而是与三磷酸腺苷依赖性染色质重塑基因的SWI/SNF家族相似，这表明DDM 1在DNA甲基化中起间接作用。在这里，我们表明，DDM 1也需要维持组蛋白H3甲基化模式。在野生型异染色质中，转座子和沉默基因与组蛋白H3在赖氨酸9处甲基化相关，而已知基因优先与甲基化赖氨酸4相关。在ddm 1异染色质中，DNA甲基化丢失，赖氨酸9的甲基化大部分被赖氨酸4的甲基化取代。由于DNA甲基化最近被证明依赖于组蛋白H3赖氨酸9甲基化，我们的研究结果表明，转座子甲基化可能是由组蛋白H3甲基化在植物基因组中。这将解释一旦组蛋白H3甲基化模式改变，低甲基化DNA的表观遗传。
The Arabidopsis gene DDM1 is required to maintain DNA methylation levels and is responsible for transposon and transgene silencing. However, rather than encoding a DNA methyltransferase, DDM1 has similarity to the SWI/SNF family of adenosine triphosphate dependent chromatin remodeling genes, suggesting an indirect role in DNA methylation. Here we show that DDM1 is also required to maintain histone H3 methylation patterns. In wild-type heterochromatin, transposons and silent genes are associated with histone H3 methylated at lysine 9, whereas known genes are preferentially associated with methylated lysine 4. In ddm1 heterochromatin, DNA methylation is lost, and methylation of lysine 9 is largely replaced by methylation of lysine 4. Because DNA methylation has recently been shown to depend on histone H3 lysine 9 methylation, our results suggest that transposon methylation may be guided by histone H3 methylation in plant genomes. This would account for the epigenetic inheritance of hypomethylated DNA once histone H3 methylation patterns are altered.